CheatSheets
JavaScript Cheat Sheet
| JS Snippet | Description |
|---|---|
console.log() | Used to print a message to the console |
document.getElementById() | Used to select an element by its id |
document.querySelector() | Used to select an element by its CSS selector |
document.createElement() | Used to create a new HTML element |
element.addEventListener() | Used to attach an event listener to an element |
element.appendChild() | Used to add an element as a child of another element |
element.innerHTML | Used to access or set the HTML content of an element |
element.style | Used to access or set the styles of an element |
element.classList | Used to add, remove, or toggle a class on an element |
function foo() | Used to define a function named foo |
foo() | Used to call the function foo |
if (condition) | Used to check if a condition is true |
for (let i = 0; i < 10; i++) | Used to create a loop that runs 10 times |
const variable = value | Used to declare a constant variable with a value |
let variable = value | Used to declare a variable with a value |
array.push(element) | Used to add an element to the end of an array |
array.pop() | Used to remove the last element from an array |
array.shift() | Used to remove the first element from an array |
array.slice(start, end) | Used to create a new array with elements from an existing array |
array.map(callback) | Used to create a new array by running a callback function on each element of an existing array |
array.filter(callback) | Used to create a new array with only the elements that pass a certain condition |
array.reduce(callback) | Used to reduce an array to a single value by running a callback function on each element |
object.property | Used to access the value of a property on an object |
object.property = value | Used to set the value of a property on an object |
object.method() | Used to call a method on an object |
string.indexOf('substring') | Used to find the position of a substring in a string |
string.replace('old', 'new') | Used to replace a substring in a string with a new string |
string.split('delimiter') | Used to split a string into an array based on a delimiter |
string.trim() | Used to remove whitespace from the beginning and end of a string |
string.toLowerCase() | Used to convert a string to lowercase |
string.toUpperCase() | Used to convert a string to uppercase |
parseInt(string) | Used to convert a string to an integer |
parseFloat(string) | Used to convert a string to a floating-point number |
JSON.stringify(object) | Used to convert an object to a JSON string |
JSON.parse(string) | Used to convert a JSON string to an object |
Math.random() | Used to generate a random number between 0 and 1 |
Math.floor(number) | Used to round a number down to the nearest integer |
Math.ceil(number) | Used to round a number up to the nearest integer |
Math.round(number) | Used to round a number to the nearest integer |
Math.min(n1, n2, ...) | Used to find the minimum value from a list of numbers |
Math.max(n1, n2, ...) | Used to find the maximum value from a list of numbers |
Math.abs(number) | Used to get the absolute value of a number |
Math.pow(base, exponent) | Used to calculate the power of a number |
Math.sqrt(number) | Used to calculate the square root of a number |